Conversion of hydrocarbons in the presence of inert solids



Dec 25, 1956 c. N. KIMBERLlN, JR., ETAL 2,775,546

CONVERSION OF HYDROCARBONS IN THE PRESENCE OF INERT SOLIDS 4Sheets-Sheet l Filed June 20, 1951 T @H E o w@ c n. n C VV w n c 5 n: ubw.; hun .mm f3 M nr 5e eb u@ o Q Dec. 25, 1956 C. N. KIMBERLIN, JR., ETAL CONVERSION OF HYDROCARBONS IN THE PRESENCE OF' INERT SOLIDS 4Sheets-Sheet 2 Filed June 20, 195] Dec. 25, 1956 c. N. KIMBERLIN, JR.,ET A1. 2,775,546

CONVERSION OF HYDROCARBONS IN THE PRESENCE OF INERT SOLIDS Filed June 2O1951 4 Sheets-Sheet 4 @harLeS QKimberUn J Bru/enters United States e.non li:

This invention relates to a process for treatinghydrocarb.onsand.moreparticularly relates to the conversion 1oricrackingof-.heavyresidual petroleum oil to p1'oduce .lowerrboiling:hydrocarbons.4 v

The petroleum oil residuumor residual oil which is tobeeonvertedcaccording to the present process is ahighboiling-.hydrocarbonoil `which cannot bewvaporized.` at ordinary.pressures without cracking. the high boiling con- .stituentsr..Atvpresent there is a 4relatively/largev accumuglation of'reducedicrudegor heavy bottoms becausey lower l.grade .crude..oil feedstocksare being-processed 'which .leave morev residue andbecause there is a`larger demand "for .motorffuelsuch as 'gasoline .and other petroleumfoilproducts. such ,asheating'oil which meansprocessing frnore .crude` :oilto leavetmore residue.` Also .the tendency .is todistill the crudes torecovenhigher boiling, feedstocks .diofrv-oatalyticwcracking and. thisleaves higher boiling residualbils. f f A u f nv-It-isknown to crack orcoke heavy residual petroleum oils `in thepresence.oiiinely` dividedinert solid particles maintained as..a.uidized bed. `Such colingisdiilcult to operate at relativelylow temperatures. except ativeryllow,efeed ratesdueio tle-..sticky feedcausingloss ofjluidity in the-bed ofsolids. .In delayed colcing, the-,process is Adiscontinuous and:lpresents a problem oi ,removingwgcoke -ronr the coking vessel..AnotherY known processofpQksing is.one.wherethe, residuum is sprayedontoa moving fbedrofhot coke .but this process ,requires large and yeX-v pensive equipmentand :is inoperable below about 930 exceptat .very-low-residuum feed rates-because of-.fthe 1' bridging yof .themovingcoke bed-, by .the stickyresiduum ,-feedL f .;1 1 n." r. A.' ..:.-Qtherconversion processesy are known wherein the residuum or heavy petroleumresidualoil is-heated in a :g ,coil fand/or. .soaking :f,drum under..sufficient,Y pressure to prevent 7distillationo the gas oil asitis,produced but, in this type otr-.process the coke-,remainslargelywsuspended theeoil. and the only means. available,heretoiorehasbeen lti'ation or centrifuging to remove the ookefparmticles; neither ofwhichds desirable. `When operating at ,-:desirably L-highconversionsthe. reaction vproducts directly`from .the conversion vzonecannot befeddirectlydo a `distillation zonedue, tothe high-.content ofucoke which1..would resultin fouling of the Vdistillation equipment,

u The..pre`sentinvention `overcomes Ytheobjections `and shortcomings ofprior process by providing`- an improved distillation zone for the,productsofconversion leaving jithe coking zone. The productsofconversion orcolring are flashed or sprayedinto or onto .a lluidized bedof ^heatediner-t solids, preferably coke particles. The uid- "likedv bedof solids is maintained at a temperature of about 900 F. to 1050 torapidly vaporize the distillable oil leaving thelcoke particlesY behindin the ludized bed.

wgfhelheated fluidized bed of solids acts as a distillation -zoneprimarily and not as a `coking or conversion zone.

Vrious`modications of the inventionare presented Va williappearrfrom thedetailed description to be given after.

`for vacuum residua. 30

2,775,546 atented Dec. 25, 1956 ICC In the drawings:

Fig. .1 represents one form of apparatus adaptedto carry outrthe processof the invention;V i

.Fig 2 represents a modification in which some of the coke is burnedinthe distillation zone and heat issupplied to the coking step bysubmerging a coking coil inthe iluidized bed in the distillation `zone;v

Fig. 3 represents a modification where some of the coke isburnedrin acoil submerged in the iluidized bed inthe distillation zone to`indirectly supply heat tothe distillation zone; and v Fig. 4 representsanother modification in which the iluidized solids bed distillationzoneis maintained under vacuum. l

Referring now to Fig. 1 of the drawings, the referencecharacterltldesignates a line` for feeding heavy residual petroleumoil', to a preheating coil 12 anda coking or conversion Vzone 14 whichmay bea coil or coil and drum or a drum for icokingthe residual `oil andto produce vcokegas and distillable oils including gasoline, heating4whole petroleum crude oil, ,tars, pitches, s hale oil, heavy cycle oil,etc, The residual oil mayhave a gravity of about l'0 to 20 API andaConradson carbon ofabout 5 to 30 wt. percent andan initial boiling pointabove about 800 F.` for atmospheric residua or above about 1050 `F.

The oil is heated in coking zone 1d to a temperature of about 750 to 950and is -nfiainntained under a pres- (sure of about 100 to 3000 poundspersq. in.` gage with the residence timerbeing-about 2 Vto`240 minutesdepending onthe vtemperature selected and the degree* of conversiondesired. ToF avoid coke adhering `to the internal walls ot 'the coil` ordrumvit isrpreferred to add nely divided solids preferably coke of asize of about 5 toV 250 microns to the oil feed through line 16 to servefas nuclei upon which coke formed during colingis deposited. vThe addedcoke particles also act toV scour andclean the walls ofthe-coking zone.The amount of solids added through line ld is about l5 to .100 lbs. perbarrelof yoil..fered, preferably about 30 to 60llbs.` per-barrel.

A diluentsuch as steam orllowerl boiling kpetroleum fractions maybeadded to theresidual oil feed through K -line` `1&5 to aid invaporization of the residual oil'or tonirnv#prove product distributioninthe' coking Vzone and to improve volatilityffin the iluidfdistillationzonen When processing theVery heavy vacuum residual oils, itjis,particularlydesirable to add a diluent of lower'bQiling petroleumfraction such as a heavy naphtha'boiling in 'the rangeor" about' 250 to5001 F. This naphtha diluentlmay be added in amounts' of 20 to' 120 vol.vper- ;Cent, preferably'rabout 50 to 100 vol. percent of theresidual'oil to be processed. rThis naphthadiluent decreases' the`viscosity of the residual oil.thus permiting greater turbulence and a'more `effective scouringaction on the vessel walls by the seed cokewith the resultthat foulingofthe wallsis avoided. t

r The total products of conversion or coking inthe iorm of a slurry ofcoke in liquid oil leave coking zone`f14 through line'22 and are passedtoa'uidized solids dis- -tillation zone 24 -maintained at a temperatureof about 800 to 1050 F.V and under a pressurefof about 0 to 25 lbs. persq. in. gage.y Substantially all of the cracking or coking has takenplace in` coking zone 14 so that the tainsfthe bed iluidized having alevel indicated at 28 with a dilute phase 32 thereabove. The density ofthe fiuidzed bed when using nely divided coke having a particle size ofabout 100 to 400standard mesh is about l5 Ito 40 lbs. per cu. ft.Preferably a gas-solids separating meanssuch as a cyclone separator (notshown) is arranged in the upper part of the distillation zone 24 toremove etrained particles from the vaporous .products leaving thedistillation zone 24 through outlet `line 34 and return them tothewden'se b'ed 26.

The total products o'f coking from line 22 may pass through pressurereducing valve 35 in line 36 where they 'are dashed or sprayed through aspray nozzle device 38 'above llevel 28 and onto the top of densefluidized bed 26 `1-11 d1st1llation zone 24. Due to the reduction inpressure some .of the coking products are immediately flashed orvaporized and pass overhead through line 34 to a fractionatcr tower r42presently to be described. The nonvaporiz'ed constituents drop into thefluidized bed 26 and me ve'poiiz'ed and pass overhead through line 34 toleave 'only the coke particles in the bed 26. Alternatively, the totalproducts of :colcing may be passed through line 44 anto ruidizedbed 26below the level 28 thereof.

For supplying heat to the distillation zone '24, lluidized Y 'coke orsolid particles containing coke formed during cokng and coking vessel`14 are withdrawn from 4the bottom of distillation zone 24 by means of astandpipe 46 having a control slide or other valve 48 to control therate of Withdrawal* of solids from zone or vessel 24. The with- `drawn.solids yare picked up by air or other oxidizing gas lintroduced throughline i512 .and the resulting suspension .passed through line 54 into thelower portion of a burning o r heater vessel 56 provided with a densefluidized `-turbulent bed 58 of solids having a Ilevel indicated at '62:with la dilute phase 6-4 thereabove. The supericial Velocllty bf thegasiform material passing upwardly through some solids which are carriedover into the fractionator 42through line 34.

Referring now to Fig. 2 of the drawings, the reference character 102designates a feed line -for the heavy residual oil feed into which steamor light petroleum oil diluent may be 4introduced through line 104,bottoms recycle through line 106 and coke particles to serve as nucleifor coke and for scouring the coil heater 108 introduced through line1512. Steam may be used .as the carrying gas for said coke as shown inline 113. The residual oil admixed vwith other materials passing throughpreheater 108 is then passed through coil heater 112 most of which issubmerged in uidized solids bed =114 in distillation vessel 11-6. -Thedense fluidized highly turbulent bed 114 has a level indicated at 118.above whic-h is .a disperse or dilute phase 122. The oil passingthrough coil heater 112 is heated to colting temperatures of about 900F. to 1000 and is maintained under a pressure of about 500 to 3000 lbs.per sq. in. gage and the residence time of the oil in heater 1112 isabout 2 to 5 minutes.v The oil 'in heater 112 receives heat from thedense fiuidized bed 114 by indirect heat exchange.

The upper or outlet end of coil heater CD12 extends abo-ve the level 118in vessel 116 and at its extremity is directed downward and providedwith a nozzle member 124 for spraying .the liquid products `of colcingonto the bed 114. Adjacent nozzle member 124 the upper end of vessel 5'6is selected to be between about 0.5 and 2.5 feet l -per second to give adensity of the bed of about l5 to 40 lbs. per cu. .f-t. when using100-400 mesh coke or finer. rIhe heater 56 is maintained at atemperature to heat the solid particles to a temperature of :about 1000F. to 1400 I".

jIot combustion gases pass overhead through a gassollds separatingdevice such as a cyclone separator 66 ror removmg entrained solids fromthe combustion gases and returning them'to bed 58 via dip leg 68. Thegases pass overhead-through line 72 and may be passed through a Wasteheat boiler or the like to recover heat therefrom. The heated solids arewithdrawn from the bottom heater 156 through a standpipe 7'4 having acontrol valve 76 and Ijllked 11p by a .gas such as steam introducedthrough line .78. The resulting suspension is passed through line 82rand returned to the lower portion of the distillation zone 24 whereythe heated solids supply heat for distillation. .Excess coke particlesare withdrawn from fluid bed 26 'through Withdrawal line 84. The amountof steam and .'gaSeS Passing upwardly through bed 26 in distillationZOU@ 2/6 is selected so that the superficial velocity of the'llpllowiing gasif-orm material is between about 0.5 to 2.5 Pfer sec. to.give the density of bed 26 above referred I The vaporous products ofcoking lealving the top of listillation zone 24 `and passing throughline 34 are fracni'onated in fractionatng system 42 to separate la light-tnaction comprising gas and about 430 F. end point lgasoline withdrawnthrough line -86 which is .further treated vas desired ito recovergasoline. From the upper corti-on of `fractionator 42 through line 88 isrecovered heating oil of about 430 to 650 F. boilin-g range and "lowerdown through line 92 is recovered a gas oil boiling between yabout 650and 1000 which is suitable as a 'v stock 'for catalytic cracking. Abottoms fraction boiling above .about l000 F. is withdrawnfrom`fractiona'tor 42 f through line 94 and may be removed from theprocess through line 96 but is preferablyV recycled to eedline 10 aheadof preheater 12. The bottoms fraction contains coil heater 112 isprovided with a pressure release valve 1526 to ash the products ofcoking so that vapors are released and pass upwardly out through outletline 128 into tractionating system 132 similar to that above described'in connection with Fig. l. The distillation vessel 1t1i6 is maintainedat a temperature of .about 900 to 1050 F. and under 1a pressure of about0 to 25 lbs. per sq. in. gage. Vaporized and distilled products passoverhead through `line 128 but are preferably irst passed through -agas-solids separating means such as a cyclone separator (not shown) toseparate most ofthe entrained solids from Ithe outgoing vapors andgases.

The distillation vessel is heated by introducing air or oxygen throughline 1'34 into the uid bed of coke l1=14 to Iburn some of the coke. Theproducts o'f combustion pass out with the conversion products throughoutlet line 128. These combustion products dilute the" dry gas producedin the process; however, this slight degradation in the value of thisfuel gas is oiset by the great economy of heating the uidized solidsdistillation-zone by the direct injection of oxidizing gas into themassof duidized coke. Excess coke in the form of finely divided solids iswithdrawn from the dense bed '114 through line 136. Coke particles inheated condition are withdrawn trom the bottom portion `of distillationvessel 116 and passed through line 112 for admixture with the residualoil as -above described. Instead of using coke from vessel 1-16, cokeparticles from an external sourcemay be passed through line 112.

Bottoms withdrawn from fractionating vessel 132 are recycled throughline 106 to feed line 102 but may be withdrawn from the process throughline 138.

Referring now to Fig. 3 of the drawings, the reference character 152designates a line for feeding residual oil together with steam or lightpetroleum oil diluent and added coke particles, if desired, to heatingand coking coil 154 substantially completely submerged in the upperportion of a dense fludzed turbulent bed of coke particles 156 indistillation zone 158. vThe dense bed 156 A has a level indicated at 162with a dilute or disperse phase 164 thereabove. The upper portion ofcoil 154 extends above the level 162 of the dense bed and is thendirected downward with the outlet being provided with a spray or nozzlemember 166 for spraying the products of coking onto the dense bed 156.The. outlet end of coil 154 is provided with a vpressure release valve168 adjacent nozzle member 166. The .temperature and "pressureconditions in coil 154 are substantially the same asin the coking coilof Fig. 2. The distillation zone functions similarly to that describedin Figs. 1 andV -2 in that coke particles are separated from distillableoilsand gases formed4 by a coking process.

:Steam is introduced into the lower portion of distillation vessel 158throughline 172 to assistv in maintaining they particles in denseiluidized condition in distillation vessel `158 and to aid invaporization of the coledproducts. Arranged and submerged in the lowerportion of the fluidized solids bed 156 in distillation vess`e1`158 is acoil 17,4- for Supplying heat to the fluidized bed Vof soilds` 1 56 byburningfcoke particles or coke in the coil. Cokefcontaining particlesare withdrawn from the lower portion of ther iluidized bed 156 throughstandpipe 176 providedwitha control valve 178. The Withdrawncoke-containing solids lare mixed with air or other oxygen containinggasV introduced through line 182 and the mixture or suspension, passedthrough line 184 and coil 174 so that thebfurningnmixture as it passesthrough coi1l174 gives. of heatwhich byindirect heat exchange isvtransfnred'to4 the luidized solids bed 156. The ilue gas"l or gases ofcombustion leave the coil 174 through line 186Yand mayhefpassed througha Waste heat boiler to recover heat therefrom. M

Excess coke may be withdrawn from the fluidized bed I156 yof solids vialine 18.8. Vaporous and gaseous pr'oducts leave overhead through line192k after having preferably passed through agas-.solids separatingdevice and are introduced into a fractionating system or the like asdescribed in` connection with Fig. 1 above.

Referring now toFig. 4 of the drawings, the residual oil feed is "iirsttdistilled under a vacuum or subatmospheric pressure lto remove some ofthe vaporizable constituents therefrom;M andV the thus. treated residualoil is coked and then distilledundersubatmospheric pressure.

The residualoil which is of the type above described is` passed through.line 202 and preheater coil 204. where it is heated toa temperaturewithin the range of about 400 to 750 As abovel described. steam may beadded to the residual. oil and, also. coke particlesA as nuclei forthecoke formedmay be added. The` heated residualoillundena pressure ofabout. 10 to 100.*lbs.. per sq. in. gageis passedthrough valved` line206.to.a.dis tillation tower.208 maintained under a; subatmosphericpressure of about 1` to 20 inches of. mercury absolute by attaching a,vacuumpump (not. shown). and condensing system (not shown) to outletline 212 from distillation tower 208. t

Distillable vapors go overhead through line 212 and are condensed andform cracking stock for catalytic or thermal units. The unvaporizedresidual oil is Withdrawn from the bottom of tower 208 through line 214,passed through heating coil 216 by pump 218 under a pressure of about250 to 3000 lbs. per sq. in. suiiicient to prevent vaporization of theoil and heated to a temperature of about 800 to 1000 F. The oil duringcoking is preferably maintained under the above conditions for about 5to 60 minutes. Coke particles and steam or a light petroleum oil diluentmay be added to line 214 by line 219 to prevent or minimize coking ofthe oil in coil 216. The products of coking are then passed through line222 having a pressure reducing means 224 into iluidized cokedistillation zone 226 having a dense fluidized highly turbulent bed 228with a level indicated at 232 and dilute or disperse phase 234thereabove. The outlet end of line 222 is provided with a nozzle orspray member 236 preferably directed downward so that the products ofcoking are sprayed or ashed in a downward direction onto the dense bed228.

Vapors from the products of coking pass overhead through line 238 todistillation tower 208 to separate high boiling fractions and to removeany entrained solids and unvaporized liquids. Vapors from line 238 areintroduced at a lower point than the residual oil feed introduced vialine 206. so that. the latter may exertl a scrubbing action. upon theformer. Inv this manner vaporization of the lighter fractions of theresidual feed is aided while the heavier portions of `thevapors fromline 238 are condensed and the entrainedr solids and unvaporized liquidparticles are scrubbed out. Coke dis-1 tillation zone 226` is maintainedunder a subatmospheric pressure of about 1 to y20 inches of mercuryabsolute. Steam is supplied throughline 242 to fluid. bed 228 in thecoke distillation zone tomaintain the bed in a dense fluidized highlyturbulent condition and to aid in vaporie zation. The supercial velocityof the steam Apassing upwardly through the iluidized bed of solids 228is between about 0.5 and 5.0 feet per second when the solid particlesare of a size between about and 400 mesh or finer.

Heat is supplied to the coke distillation zone to maintain it at atemperature of between about 800 and l050 F. by burning coke particlesina coil submerged in the bed 228.` Coke particles are Withdrawnfrom thebottom of the fluidized bed 228- and passed to standipe or barometricleg 244 provided at its lower-` end with a control valve 246 forcontrolling the rate of withdrawal of coke from the fluidized bed 228.`Air introduced through line 248- picks up the withdrawn coke or cokecontaining particles and forms a suspension which is passed through line252 and through coill 254 submerged in the lower portion of thefluidizedbed 228 in the distillation zone 226; In this way heatfrom the burningcoke is supplied to the iluidized bed 228 by indirectrheat exchange.Thehot combustion gases leave coil 254 through 'outlet 1ine-256and maybe passed through a waste heat boiler, if desired, to recover heat fromthe hotcombustion gases.

Excess coke may be withdrawn from Huidized bed 228 via line 258.

In all the above forms of the invention inert materials such as sand,pumice, kieselguhr, Carborundum, etc., but preferably nely,dividedpetroleum coke is used to form the lluidized bed in thedistillation zone and' some inert Solids in finely divided form may beadded in amounts lof l5 to 100 lbs. per barrelof' feed to keep theinterior of the coil` or coking equipment clean of coke; During thecoking operation coke is formedand excess coke in iinelydivided'formis'removed from the process.

The conversion ofthe residual-oil, reducedcrude, whole crude, etc., issubstantially complete to coke, gas` and distillable oil before itenters the distillation zone where the gas oil is rapidly vaporized andleaves the distillation zone after only negligible contact time. Becausethe conversion of the heavy residual oil is substantially complete inthe conversion coil or equipment, the use of a relatively hightemperature in the fluidized bed distillation zone does not adverselyaffect the product quality. The fluidized bed distillation zonefunctions as a means for distilling the gas oil product from the cokeand forms an excellent way of separating coke particles formed duringthe coking or conversion of the heavy residual oil from distillable gasoil.

A specific example will be given with reference to Fig. 1. A vacuumresiduum derived from a mixture of West Texas and South American crudeoils and having an API gravity of about 7.4; a Conradson carbon of about20 wt. percent, a viscosity greater than 1000 seconds Saybolt Furol at210 F., and an initial atmosphelic pressure boiling point above about1050o F. is diluted with 106 volumes of naphtha boiling in the range ofabout 300 to 400 F. per 100 volumes of residuum. Seed coke having aparticle size of 100 to 200 mesh is added in amounts of 55 lb. perbarrel of mixed feed. The mixed feed containing seed coke is introducedinto heater 12 and soaker 14 and heated to about 800 F. at about 2100 p.s. i. g. pressure. Turbulence is maintained in soaking zone 14 by meansof mechanical agitation. The residence time of the oil in liquid phasein heater 12 and soaker 14 at temperatures above about 775 F. is

about 150 minutes. Under these conditions the residual' feed issubstantially completely converted to coke and distillable 4productswithout fouling of the'vessel walls. The coked products from soakingZone 14 are introduced into uid solids distillation zone 24 containing abed of fluidized coke maintained at about 900 F. and 0 p. s. i. g. Steamamounting to about wt. percent of the oil feed is introduced intodistillation zone 24 to maintain the coke in a fluidized condition andto aid in the distillation process. The coked oil feed rate todistillation zone 24 is about 5 weights per hour per weight of coke inzone 24. As the coked oil is sprayed onto the hot iluidized coke in zone24 it is rapidly vaporized and removed overhead by line 34 withoutsubstantial further conversion in zone 24. The coke content of the cokedoil entering zone 24 amounts to about 86 lbs. (including the 55 lb. ofseed coke introduced with the feed) per barrel of residuum plus naphthafeed; this coke remains in zone 24 in a dry, finely divided form andbecomes a part of the lluidized mass in this `Zone. rl`he distillatefrom zone 24 is introduced into a fractionator 42 and fractionated intogas, gasoline, heating oil, gas oil and bottoms. From each barrel ofmixed residuum plus naphtha feed the following products are obtainedfrom the distillation zone; (l) about 16.7 lbs. of dry gas, (2) about 24gal. of gasoline cut boiling below about 430 F. (including the naphthaintroduced in the feed as diluent), (3) about 4.8 gallons of heating oilboiling in the range of about 430 to 650 F., (4) about 7.5 gallons ofgas oil boiling in the range of about 650 to 1000 F. suitable forcatalytic cracking feed, and (5) about 1.5 gallons of higher boilingbottoms suitable for fuel oil or for recycling to the process.

What is claimed is:

1. A residual oil conversion process which comprises coking a residualoil in liquid phase in a coil and ydrum cokng zone at a cokingtemperature in the range of 750 to 950 F., a pressure in the range of100 to 3000 p. s. i., and for a time in the range of 2 to 240 minuteswhile in admixture with to 100 lbs/bbl. of coke particles of a size inthe range of 5 to 250 microns and in admixture with to 120 vol. percentof naphtha diluent boiling in the range within the limits of 250 to 500F. to obtain coke, distillable oils and gas, ashing the total efuentfrom said coking zone directly into a distillation zone containing adense turbulent bed of fluidized coke particles maintained at atemperature in the range of about'800"F. to 1050- F. and aepressureinthe range of 0 to 25 p. s. i. gauge to obtain said distillable oils asvapors without substantial coking and relatively dry coke, said drycokebecoming a part of said dense turbulent fluidized bed, recovering saidvapors overhead Afrom said distillation zone as product, circulating aportion of said dense turbulent bed to a fluid solids heating zonewherein the solids are heated by combustion, and returning heated solidsto said distillation zone to supply heat thereto.

2. A process for the conversion ofheavy residual petroleum oilscontaining extremely high boiling constituents, which comprises heatingresidual oil in a suspensoid coking coil zone at a coking temperature ofabout 750 F. to 950 F. and a pressure of about 100 to 3000 lbs. per sq.in. in liquid phase for about 2 to 240 minutes to convert the residualoil substantially completely to coke, distillable oil and gas, passingthe total products of coking `to a distillation zone containing arelatively dense bed of nely divided cokeparticles uidized by upflowinggases and maintained at a temperature of about 800 VF. to 1050 F. and apressure of about 0 to 25 lbs. per sq. in. gauge so that the products ofcoking .are llashed and distillable oils are taken overhead withoutsubstantial further conversion while the coke particles are separatedand collected in the dense fluidized bed.

3. A process according to claim 2 wherein the heating of the residualoil is carried-out in a coil submerged in said dense uidized bed in saiddistillation zone and heat is supplied to said dense fluidized bed bywithdrawing a porton of the coke partclesfromsaid dense bed and burningthe Withdrawn coke particles in a coil submerged in said dense iluidizedbed in `said distillaton zone to supply heat thereto by indirect heat4exchange.

References Cited in the le .ofthis patent UNITED STATES PATENTS2,382,755 Tyson Aug. 14, 1945 2,388,055 Hemminger Oct. 30, 19452,436,938 Scharmann et al Mar. 2, 1948 2,447,149 Wier Aug. 17, 19482,471,104 Gohr May 24, 1949 2,485,315 Rex Oct. 18, 1949 2,527,575Roetheli Oct. 31, 1950 2,557,748 Liedholm J-une 19, 1951 2,598,058Hunter May 27, 1952 2,675,294 Keith Apr. 13, 1954

1. A RESIDUAL OIL CONVERSION PROCESS WHICH COMPRISES COKING A RESIDUALOIL IN LIQUID PHASE IN A COIL AND DRUM COKING ZONE AT A COKINGTEMPERATURE IN THE RANGE OF 750* TO 950*F., A PRESSURE IN THE RANGE OF100 TO 3000 P.S.I., AND FOR A TIME IN THE RANGE OF 2 TO 240 MINUTESWHILE IN ADMIXTURE WITH 15 TO 100 LBS./BBL. OF COKE PARTICLES OF A SIZEIN THE RANGE OF 5 TO 250 MICRONS AND IN ADMIXTURE WITH 20 TO 120 VOL.PERCENT OF NAPHTHA DILUENT BOILING IN THE RANGE WITHIN THE LIMITS OF250* TO 500* F. TO OBTAIN COKE, DISTILLATE OILS AND GAS, FLASHING THETOTAL EFFLUENT FROM SAID COKING ZONE DIRECTLY INTO A DISTILLATION ZONECONTAINING A DENSE TURBULENT BED OF FLUIDIZED COKE